When buying a live Siamese fighting fish (Betta splendens) it is wise to closely observe the condition of the fishes fins (no fungus or other damage), scales (none missing and nice and glossy), eyes (clear and not sunken or sticking out) and also check that its tummy is not sunken or distended in any way. I would also hold a mirror up to the fish and see if and how he displays. If all the fish are good on those observations then I would simply choose by my preference and purity of colour.
Of course they can. How else would we have fighting fish.
Fish are not stupid. There is no chance that a Betta splendens would mistake a guppy for another Betta.
their reflection, or another fighting fish. They see their reflection and think it's another fish
they do fight.
No, fighting fish (Bettas) are only interested in fighting with other fighting fish.
The male Betta will only fight another male Betta. They are slow, timid and peacefull fish except when another fish of the same sex and species is in the same vicinity.
A betta fish? You can't or they will kill the tank partner
their reflection, or another fighting fish. They see their reflection and think it's another fish
No fish will really fight a Betta,unless its another Betta(male,not female,males and females get along pretty well),so i would suggest getting a Gold Mystery Snail if you dont want your Betta fighting with your fish.
Win what? be more specific. If you mean in a territorial dispute, an adult fighting fish will get eaten (literally) by and adult convict cichlid. but if the cichlid and the fighting fish are of the same size then the fighting fish would be at an advantage.
That would be the Siamese Fighting Fish
The axolotl would probably rip bits off the Betta and kill it. Male Bettas are quiet peacefull fish and they will only fight with another male Betta.